Liquid 2-(2-hydroxy-3-higher branched alkyl-5-methyl-phenyl)-2H-benzotriazole mixtures, stabilized compositions and processes for preparing liquid mixtures

ABSTRACT

Liquid 2-(2-hydroxy-3-higher branched alkyl-5-methylphenyl)-2H-benzotriazole mixtures are prepared by alkylating 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole with a straight chain alkene or with a branched chain alkene of 8 to 30 carbon atoms in the presence of an acidic catalyst at 100°-200° C. The liquid mixtures exhibit outstanding efficacy in protecting organic substrates from light induced deterioration as well as good resistance to loss by volatilization or exudation during the processing of stabilized compositions at elevated temperatures.

BACKGROUND OF THE INVENTION

The present invention relates to selected liquid2-aryl-2H-benzotriazoles which are useful in protecting light-sensitiveorganic materials from deterioration and to stabilized compositionscontaining said benzotriazoles.

The UV-absorber of the o-hydroxyphenyl-2H-benzotriazole class have longbeen known as effective light stabilizers for organic materials and haveenjoyed considerable commercial success.

The description, preparation and uses of these valuable2-aryl-2H-benzotriazoles are further taught in U.S. Pat. Nos. 3,004,896;3,055,896; 3,072,585; 3,074,910; 3,189,615 and 3,230,194.

However the hitherto known 2-aryl-2H-benzotriazoles of this group havein some circumstances exhibited limited compatibility in certainsubstrates, and excessive tendency to exude, sublime and/or volatilizeduring processing of stabilized compositions into sheets, films, fibersor other pellicles when processing must be done at elevatedtemperatures. Likewise such benzotriazoles may also suffer undue loss byvolatilization or sublimation from fabricated structures, particularlythin films or coatings, especially when subjected to elevatedtemperatures during use.

Attempts have been made to increase compatibility and to reducevolatilization loss by modifying the structure of the benzotriazoles.

In U.S. Pat. No. 3,230,194, a higher alkyl group was substituted formethyl and the latter compound2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole exhibited superiorcompatibility and performance in polyethylene compared to the former.

In U.S. Pat. Nos 4,283,327, 4,278,590 and 4,383,863 there is described2-(2-hydroxy-3,5-di-tert-octylphenyl)-2H-benzotriazole which exhibits anexcellent combination of compatibility with and/or solubility innumerous polymeric substrates along with superior resistance to lossfrom stabilized compositions during high temperature processing or inend-use applications where coatings or films of the stabilizedcompositions are exposed even to ambient weathering and light exposures,and in photographic applications. However,2-(2-hydroxy-3,5-di-tert-octylphenyl)-2H-benzotriazole is still a solid(melting point 105°-106° C.) which requires in many end-use applicationsthe concomitant use of a solvent or dispersing diluent to allow for itto be used in practice. Such solvents or diluents are undesired forreasons of cost and environmental and other considerations.

U.S. Pat. Nos. 3,983,132, 4,096,242 and 4,129,521 describe liquidmixtures of 2-(2-hydroxy-5-nonylphenyl)-2H-benzotriazoles or of2-(2-hydroxy-5-dodecylphenyl)-2H-benzotriazoles and stabilizedcompositions using said mixtures where the nonyl or dodecyl groups eachrepresent an isomeric mixture of secondary and tertiary nonyl or dodecylgroups attached to the para position relevant to the hydroxy group onthe 2-phenyl moiety in the 2H-benzotriazole. The isomeric nonyl ordodecyl groups are introduced into the phenol before it is coupled withthe 2-nitrophenyldiazonium salt in a classic 2H-benzotriazole synthesis.

The instant liquid benzotriazoles differ from the benzotriazoles ofthese three patents by the method by which they are prepared, by thelocation of the branched alkyl group ortho to the hydroxy group and byin part the nature of the branched alkyl group itself when prepared froma straight chain alkene.

The liquid mixtures prepared by the method of U.S. Pat. No. 4,129,521have no substitution in the ortho position relevant to the hydroxy groupthus making said compounds prone to interaction with metal ions duringresin curing and in other end-use applications in polymer substrates andwhich may lead to deleterious effects on color, light stability andancillary properties. The instant mixtures are substituted in the orthoposition relevant to the hydroxyl group and do not have this problem.

Certain hydrophobic non-diffusing hydroxyphenylbenzotriazoles aredisclosed as very useful as ultraviolet light absorbers in photographicgelatin layers (U.S. Pat. No. 3,253,921). The instant benzotriazoleswith their liquid or non-crystalline nature, their desirable absorptioncharacteristics in the ultraviolet range and their photographicinertness are particularly useful in photographic compositions,especially in protecting color dye images against the harmful effects ofultraviolet light.

U.S. Pat. No. 3,253,921 discloses benzotriazoles broadly, but does notexemplify the instant benzotriazoles which are particularly effective instabilizing photographic compositions against the harmful effects ofultraviolet radiation.

Further background in the area of stabilization of photographic dyeimages is provided by U.S. Pat. No. 4,042,394 which describes thevarious components in photographic compositions and the requirements forstabilizing photographic dye images.

U.S. Pat. Nos 4,383,863 and 4,447,511 describe the use of2-(2-hydroxy-3,5-di-tert-octylphenyl)-2H-benzotriazole in photographicelements and compositions. While this discrete benzotriazole exhibitsenhanced solubility in the various solvents and diluents used inphotographic elements, such solvents and diluents are still requiredsince said benzotriazole is still a crystalline solid.

The instant benzotriazole mixtures are liquid or non-crystalline leadingto the need for less or no solvent or diluent, thinner photographiclayers and all the concomitant economic benefits flowing therefrom.

DETAILED DISCLOSURE

This invention pertains to selected liquid or non-crystalline2-aryl-2H-benzotriazole light absorbers and to organic materials, bothpolymeric and non-polymeric, stabilized thereby, as well as tophotographic elements containing said liquid materials. The stabilizedcompositions include plastics, coatings, fibers, films, and photographicsubstrates.

Another object of this invention is the process for preparing saidliquid or non-crystalline mixtures of benzotriazoles. These liquidmixtures exhibit great resistance to volatilization, enhanced solubilityin selected solvents, desirable absorption characteristics in theultraviolet range and photographic inertness. This combination ofproperties makes these benzotriazoles particularly useful inphotographic compositions especially in protecting color dye imagesagainst the harmful effects of ultraviolet light.

More particularly, the instant invention pertains to a normally liquidor non-crystalline mixture of benzotriazoles, suitable for stabilizingorganic materials against light-induced deterioration, which consistsessentially of compounds of the formula ##STR1## wherein

T₁ is hydrogen or chloro, and

T₂ is a random statistical mixture of at least three isomeric branchedsecondary alkyl groups each having 8 to 30 carbon atoms and having theformula ##STR2## where E₁ is a straight-chain alkyl of 1 to 14 carbonatoms and E₂ is a straight-chain alkyl of 4 to 15 carbon atoms where thetotal number of carbon atoms in E₁ plus E₂ is 7 to 29.

Preferably T₁ is hydrogen.

Preferably T₂ is alkyl of 8 to 16 carbon atoms and most preferably isalkyl of 10 to 12 carbon atoms.

These preferred and most preferred values for the carbon atom contentfor T₂ determine likewise the preferred and most preferred values for E₁and E₂ whose sum in carbon atoms is one less than the total for T₂.

Another embodiment of the instant invention relates to a normally liquidor non-crystalline mixture of benzotriazoles, suitable for stabilizingorganic materials against light induced deterioration, which consistsessentially of compounds of the formula ##STR3## wherein

R₁ is hydrogen or chloro, and

R₂ is a random statistical mixture of at least three isomeric branchedalkyl groups each having 8 to 30 carbon atoms and having a multiplicityof alkyl branches along the main alkyl chain.

Preferably R₁ is hydrogen.

Preferably R₂ is alkyl of 8 to 16 carbon atoms and most preferably isalkyl of 9 to 12 carbon atoms.

The 2-(2-hydroxyphenyl)-2H-benzotriazole light absorbers areconventionally obtained by coupling an appropriately substituted phenolwith an o-nitrophenyl diazonium salt to prepare an o-nitroazobenzeneintermediate which is subsequently reduced and cyclized to thecorresponding 2H-benzotriazole.

It is clear that any change in the nature of the substitution on thephenol moiety, for example for the purpose of modifying final2H-benzotriazole properties, must be carried out on the phenol moleculeitself before the conventional 2H-benzotriazole synthesis is begun. Thisrequires one or more additional steps in the synthetic sequence for eachnew 2H-benzotriazole product. Moreover, unavoidable side reactions occurduring these steps which make it necessary to include at least onecrystallization step in order to obtain a product of acceptable purity.

The above procedure is poorly adapted for the preparation ofnon-crystalline or liquid products where purification by crystallizationis not possible.

Indeed the process described in U.S. Pat. No. 4,129,521 discloses that,in order to obtain liquid products of acceptable purity, it is necessaryto (1) vacuum distill the crude 2H-benzotriazole product, treat the oncedistilled product with acetic anhydride to remove various undesirableimpurities; carry out a second vacuum distillation on the acetylatedmixture; blow the distillate with air at elevated temperature for manyhours and finally distill the material for a third time under moleculardistillation conditions. Only then after these laborious andeconomically unattrative procedures is a liquid product useful as alight absorber obtained.

Clearly a better method of making liquid or non-crystalline2H-benzotriazoles was needed since the conventional approach ofpreparing an alkylated phenol and then the benzotriazole from saidphenol involves an almost impossible task of removing undesirableimpurities from the benzotriazole in a practical manner.

The approach of alkylating a preformed 2H-benzotriazole was not believedpromising since it was known that phenols substituted in the orthoposition by a 2H-benzotriazolyl moiety are vastly deactivated in respectto electrophilic substitution (=alkylation) on the phenolic ring.

It was thus surprising that direct alkylation on the phenolic ring ofpreformed 2H-benzotriazoles could be carried out to give the desiredmixed alkylated products in a facile and direct manner.

Thus the direct alkylation of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole with an alpha-olefin orstraight chain alkene; or with a branched alkene not only proceeded, butoccurred in excellent conversions (over 90%) of the preformedbenzotriazole to alkylated products.

Since the 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole is alreadysubstituted in the para position to the hydroxyl group, alkylation isperforce directed to the ortho position to the hydroxyl moiety to obtaina mixture of 2-(2-hydroxy-3-higher branchedalkyl-5-methylphenyl)-2H-benzotriazoles.

The nature of the higher branched alkyl groups inserted into thebenzotriazoles depends on which type of alkene is used for thealkylation. The use of an alpha-olefin or straight chain alkene leads tothe insertion of branched secondary alkyl groups while the use of abranched alkene leads to branched alkyl groups having a multiplicity ofalkyl branches along the main alkyl chain.

More particularly the first process is a process for preparing anormally liquid or non-crystalline mixture of benzotriazoles, suitablefor stabilizing organic materials against light induced deterioration,which constist essentially of compounds of the formula ##STR4## wherein

T₁ is hydrogen or chloro, and

T₂ is a random statistical mixture of at least three isomeric branchedsecondary alkyl groups each having 8 to 30 carbon atoms and having theformula ##STR5## where E₁ is a straight chain alkyl of 1 to 14 carbonatoms and E₂ is a straight chain alkyl of 4 to 15 carbon atoms where thetotal number of carbon atoms in E₁ plus E₂ is 7 to 29, which processcomprises alkylating a benzotriazole of the formula ##STR6## where T₁ ishydrogen or chloro, with a straight chain alkene of 8 to 30 carbon atomsin the presence of an acidic catalyst at a temperature of 100° to 200°C.

The second process is a process for preparing a normally liquid ornon-crystalline mixture of benzotriazoles, suitable for stabilizingorganic materials against light induced deterioration, which consistsessentially of compounds of the formula ##STR7## wherein

R₁ is hydrogen or chloro, and

R₂ is a random statistical mixture of at least three isomeric branchedalkyl groups each having 8 to 30 carbon atoms and having a multiplicityof alkyl branches along the main alkyl chain, which process comprisesalkylating a benzotriazole of the formula ##STR8## where R₁ is hydrogenor chloro, with a branched chain alkene of 8 to 30 carbon atoms in thepresence of an acidic catalyst at a temperature of 100° to 200° C.

Under these vigorous reaction conditions the alkylating agent (thealkene, straight or branched chain) itself undergoes a chemicaltransformation or isomerization. Accordingly the alkyl substituentsintroduced into the benzotriazole are not a single discrete moiety, butrather a random statistical mixture of isomeric groups. This randomstatistical mixture of groups (T₂ or R₂) represents a structuraldiversity which contributes to the liquid and non-crystalline physicalstate of the resulting products.

Under the instant process conditions the double bond in the alkenealkylating agent is isomerized along the carbon chain to give a randomstatistical mixture of moieties which can then be attached to thephenolic ring in the benzotriazole.

Illustrating with the alpha-olefin 1-octene, the random statisticalmixture of octyl groups which would be included as T₂ when T₂ is octylare ##STR9## Thus T₂ as octyl would lead to at least three isomerspresent in the mixture of benzotriazoles prepared.

The straight chain alkenes needed to prepare the instant benzotriazolescontaining the moiety T₂ include the alpha-olefins and straight chainalkenes having an internal double bond. During the alkylation reactionthe double bond is isomerized along the carbon chain to give a randomstatistical mixture of branched secondary alkyl groups of the formula##STR10## as discussed above.

The alpha-olefins useful in this process are for example 1-octene,1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, 1-docosene, 1-tetracosene or1-triacontene.

These alpha-olefins are largely items of commerce or are made by thetelomerizaiton of ethylene by known methods.

Straight chain alkenes containing an internal double bond may be forexample 2-octene, 4-octene, 5-decene or 9-tricosene.

These alkenes are also largely items of commerce.

To prepare the instant benzotrizole mixtures containing the moiety R₂branched chain alkenes are needed as the alkylating agent. Here again,during the alkylation reaction the double bond is isomerized along thecarbon chain and rearrangements may occur due to branching in theoriginal alkene. A random statistical mixture of branched alkyl groupseach having a number of alkyl branches along the main alkyl chain isobtained.

The branched chain alkenes useful in this process are for exampledipropylene, tripropylene, tetrapropylene, pentapropylene,diisobutylene, triisobutylene, tetraisobutylene, pentaisobutylene,2,2,4,6,6-pentamethyl-3-heptene, diisoamylene, triisoamylene,tetraisoamylene or pentaisoamylene.

These highly branched alkenes are largely items of commerce or can beprepared from propylene, isobutylene or isoamylene by oligomerizationwith acid catalysts.

That this mixture of isomeric radicals as T₂ or R₂ is critical toobtaining a liquid or non-crystalline product may be seen from the factthat, when the alkyl substitution is a specific isomer, solidcrystalline products are obtained. For example,2-(2-hydroxy-3,5-di-tert-octylphenyl)-2H-benzotriazole melts at105°-106° C.

The alkylation processes can be carried out over a range of conditionsof time, temperature, olefin to benzotriazole ratios, catalysts andcatalyst concentrations.

Sufficient time must be allowed for the alkylation to occur usuallyabout 4 hours, but reaction times in excess of 12 hours do not increaseyield of alkylated product. Preferably the alkylation reaction iscarried out for a 6- to 8-hour period.

Relatively vigorous reaction conditions are needed since the phenolicring of the starting 2H-benzotriazole is deactivated. Reactiontemperatures of 100° to 200° C. may be used. Temperatures below 140° C.give lower yields of alkylated product and temperatures in excess of180° C. produce products of lesser quality and in lower yields.Preferably the process is carried out at 140° to 170° C., and mostpreferably at 160°-165° C. where yields in excess of 90% are obtained.

In order to alkylate the 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazolethere must be at least 1 equivalent of alkene per equivalent of2H-benzotriazole. Since competing reactions are also possible underthese reactions conditions in respect to the alkene, such asdimerization, oligomerization or polymerization, yields of desiredalkylated product are usually less than 40% when a 1:1 equivalent ratioof alkene:benzotriazole is used.

Increasing the concentration of alkene in respect to benzotriazole to a4:1 equivalent ratio greatly increases yields of alkylated products toover 85%.

Larger excesses of alkene at a 6:1 equivalent ratio do not increaseyields further.

Preferably the equivalent ratio of alkene:benzotriazole in the instantprocesses is 3.5 to 4.5:1.

The acidic catalyst is selected from the group consisting of aliphatic,aromatic and substituted aromatic sulfonic acids, sulfuric acid,phosphoric acid, acidic clays and heterogenous acidic catalysts(molecular sieves).

The concentration of catalyst useful in the instant process is 0.2 to 3equivalents of catalyst per equivalent of benzotriazole, preferably 0.3to 2 equivalents, and most preferably 0.5 to 1 equivalent of acidcatalyst per equivalent of benzotriazole.

Examples of useful sulfonic acids are methanesulfonic acid,ethanesulfonic acid, butanesulfonic acid, benzenesulfonic acid,toluenesulfonic acid and dodecylbenzenesulfonic acid. Aliphatic sulfonicacids are preferable.

Commercially available acid activated clays such as Filtrol XJ-8303;Filtrol XJ-8405; Filtrol 22; Filtrol 4; and Filtrol 13 are alsoeffective alkylation catalysts in the instant processes.

The most preferred catalyst is methanesulfonic acid.

Protection against damage caused by UV light is particularly importantin photographic technology and especially in color photographictechnology.

In order to protect the components (in particular dyes and couplers)present in a color photographic material as effectively as possibleagainst destruction by ultraviolet light, UV absorbers are normallyinserted into one or more of the upper layers of the material. This iseffected as a rule by dissolving the UV-absorber in a high-boilingsolvent and dispersing this solution, in the form of very fine droplets,in the appropriate coating solution. Since these droplets have adisadvantageous effect on the mechanical properties of the layer, andcan "exude" if they are in the top layer of the material, it isimportant to keep the quantity of absorber solution as small aspossible. This also makes it possible to produce thinner layers, which,in turn, offers advantages in processing (carry-over between baths anddrying). It is therefore desirable to employ UV-absorbers which have ashigh a solubility as possible in the customary high-boiling solvents.The UV-absorbers of the state of the art, for example the stabilizersdisclosed in Japanese Application No. Sho 54-95,233 do not, to asatisfactory extent, fulfil this requirement.

It has now been found that the instant products being liquid ornon-crystalline can be used in color photographic material without theconcomitant use of high-boiling solvents or with a very minimum amountthereof. Moreover, the instant compounds are essentially non-volatileand do not exude.

A typical photographic composition comprises a paper support on whichare coated one or more light-sensitive layers and a layer containing theultraviolet light absorber in a binder so placed as to protect the layeror layers requiring protection.

It is known that ultraviolet radiation has a detrimental effect onphotographic layers. Ultraviolet radiation in light sources used forexposure of photographic products sometimes produces undesired exposureof the layer or layers of a photographic element. This is especiallytrue in photographic elements designed for use in color photography inwhich the emulsion has been sensitized to the longer wavelength regionsand it is desirable to record only the rays of the visible spectrum.

Color photographs on multilayer photographic material, particularlythose in which the dye images are formed in sensitive emulsion layers bycolor development, are susceptible to fading and discoloration by theaction of ultraviolet radiation to which the photographs are subjectedduring viewing. The residual couplers contained in the emulsion layerafter the formulation of the picture images may be attacked byultraviolet radiation resulting in an undersirable stain in the finishedphotograph. The action of ultraviolet radiation on finished colorphotographs is particularly noticeable on positive prints on paper orother opaque support since this type of print is frequently viewed indaylight which has a high content of ultraviolet radiation. Thedye-fading and discoloration effects appear to be caused primarily bythose wavelengths of light close to the visual region of the spectrum,i.e., 300-400 nm.

It is known that silver halide photographic materials can be protectedfrom ultraviolet radiation by incorporating nondiffusing ultravioletabsorbing compounds in the silver halide emulsion layers or in overlyingcolloid coatings.

A large number of ultraviolet absorbers have been proposed for this use.Ultraviolet absorbing compounds for photographic use must generally becolorless or nearly colorless, show good compatability with the mediumin which they are incorporated, be inert to other photographic addendain the element and in the processing solution, must have goodultraviolet absorptivity and be stable to ultraviolet radiation.Representative compounds for incorporation in photographic elements aredescribed for example, in U.S. Pat. No. 3,253,921.

Aromatic organic compounds such as ultraviolet absorbers, dye-formingcouplers, antistain agents, filter dyes and the like to be effectivemust be nondiffusing and adequately distributed in highly dispersed formin the aqueous photographic gelatin layers.

This can be accomplished by a variety of chemical or physical techniquesincluding the substitution of sulfonic acid or other solubilizing groupson the organic molecule; by use of a polar organic solvent imbibitionprocedures; or by solvent dispersion techniques.

The instant liquid or non-crystalline 2H-benzotriazoles are extremelyuseful as ultraviolet absorbers in photographic gelatin layers. Theyexhibit desirable absorption characteristics in the ultraviolet region,i.e., maximum absorption in the near ultraviolet and sharp cut-off justoutside the visible region, are essentially colorless, are readilydispersed or dissolved by either the solvent-dispersion or imbibitionmethods, and are photographically inert.

The instant compounds exhibit excellent compatibility characteristics inthe gelatin layers of the photographic composition which lead tocompositions essentially without haze coupled with superior protectionof the color dye images against the harmful effects of ultravioletradiation. This combination of properties clearly distinguishes theinstant benzotriazole light absorbers from the generic disclosure ofU.S. Pat. No. 3,253,921. These salubrious results are obtained when theinstant benzotriazoles are incorporated directly into the gelatin layeror by the solvent dispersion technique.

An object of the invention is to provide novel photographic elementsprotected against the harmful effects of ultraviolet radiation byincorporation of ultraviolet absorbing materials. Another object is toprovide photographic color materials containing ultraviolet absorbersincorporated in a highly stable form. A further object is to provide anon-diffusing ultraviolet absorber.

The invention relates further to stabilized organic material which is inthe form of photographic material or is part of a photographic material,the photographic material containing, preferably in top layers, 0.05 to5% by weight, relative to the photographic material without stabilizer,of a compound according to the invention.

When the instant compounds are liquid, the instant benzotriazoles areincorporated into a hydrophilic colloid by heating an aqueous solutionof said hydrophilic colloid containing the liquid benzotriazole and anappropriate dispersing agent to a moderate temperature above the easyflow point of the instant benzotriazole, agitating the resulting mixtureto obtain a fine dispersion of the benzotriazole in the colloid, andthen cooling the mixture.

When the instant compounds are not liquid at room temperature, but arenon-crystalline, the use of a minimum amount of high-boiling solvent toassist in getting the instant compound to flow is contemplated toachieve the above objects by the solvent dispersion technique toincorporate the instant compounds in aqueous hydrophilic colloidsolutions for coating silver halide emulsion layers or associatedhydrophilic colloid layers.

The preferred high-boiling solvents include di-n-butyl phthalate, benzylphthalate, triphenyl phosphate, tri-o-cresyl phosphate, diphenylmono-p-tert-butylphenyl phosphate, monophenyl di-p-tert-butylphenylphosphate, diphenyl mono-o-chlorophenyl phosphate, monophenyldi-o-chlorophenyl phosphate, tri-p-tert-butylphenyl phosphate,tri-o-phenylphenyl phosphate, di-p-tert-butylphenylmono(5-tert-butyl-2-phenylphenyl) phosphate, etc.

The hydrophilic colloids or binders advantageously include gelatin,albumin, etc., cellulose derivatives, polyvinyl compounds, etc. Thepolymeric binders include polyvinyl alcohol or a hydrolyzed polyvinylacetate; a far hydrolyzed cellulose ester such as cellulose acetatehydrolyzed to an acetyl content of 19-26 percent; a water-solubleethanolamine cellulose acetate, a polyacrylamide having a combinedacrylamide content of 30-60 percent and a specific viscosity of 0.25-1.5on an imidized polyacrylamide of like acrylamide content and viscosity;a vinyl alcohol polymer containing urethane carboxylic acid groups ofthe type; or containing cyanoacetyl groups such as the vinylalcohol-vinyl cyano-acetate copolymer; or a polymeric material whichresults from polymerizing a protein or a saturated acylated protein witha monomer having a vinyl group.

The dispersion of an instant compound in the binder material is coatedover the light-sensitive layer of the photographic element. Where thephotographic element is a material intended for use in colorphotography, the ultraviolet filter layer need not be an outer layer,but can be used as an interlayer, i.e., under the layer or layers notneeding the protection and over the layer or layers needing protection.For example, in a multilayer material comprising three differentiallysensitized layers, the red-sensitive layer being adjacent to thesupport, the green-sensitive layer being superimposed on thered-sensitive layer and the blue-sensitive layer being outermost withrespect to the other light-sensitive layers, the ultraviolet filterlayer can be placed between the blue and green-sensitive layers orbetween the green and red-sensitive layers. Similarly, in anotherphotographic element in which the layers are reversed, that is, theblue-sensitive layer is coated over the support, and the green andred-sensitive layers are superposed over the blue-sensitive layer inthat order, the ultraviolet filter layer can be over all three layers orbetween any two of the layers.

Alternatively, the ultraviolet absorbing composition can be incorporateddirectly in the light-sensitive emulsion instead of, or in addition,being present in another layer. The amount of the ultraviolet absorbingmaterial used can be varied, depending upon the effect desired and theuse that will be made of the material.

The ultraviolet absorbing compositions are coated over a wide range ofconcentrations; usually they are coated in the range of from 20 to 300mg. of ultraviolet absorbing compound per ft.² photographic element. Apreferred range is from 75 to 160 mg/ft.². The optimum coatingconcentrations will depend upon the particular photographic element tobe protected and the amount of protection desired. The optimum coatingconcentrations for a given photographic element can be determined bymethods well known in the art.

Any photographic element may be advantageously protected according tothe invention. These photographic elements may have as their support anyof the conventional support materials, such as firm supports, e.g.,cellulose acetate, etc. opaque supports, such as white pigmented film,paper and the like.

The instant ultraviolet absorbing compound are characterized by theirnon-diffusibility in coated layers, good stability in the incorporatingsolvents and their good ultraviolet absorption. Ultraviolet absorbinglayers containing the instant compounds incorporated according to thepreferred methods of the invention have unexpectedly excellent stabilityupon prolonged exposure to ultraviolet radiation which makes themideally suited for protecting photographic elements, particularly dyeimages in color materials.

The instant liquid benzotriazoles may be used advantageously inphotographic elements with other liquid ultraviolet absorbers (UVA) suchas5-chloro-2-[2-hydroxy-3-tert-butyl-5-(2-octyloxyethyl)-phenyl]-2H-benzotriazole.

The instant liquid benzotriazoles are also useful as solvents for othersolid UVA materials or for other components in a silver halidephotographic element when used alone or in combination with commonphotographic oils as described in European Patent Application Nos.84,692 and 84,694.

Such other components include

yellow, magenta and cyan couplers

DIR couplers, black couplers, colorless couplers

chromegenic coupler stabilizers

chromogenic dye stabilizers

accutance dyes, antihalation dyes, dye-bleach dyes

formaldehyde scavengers

sensitizing dyes

optical brightening agents

oxidized developer scavengers

compounds which release diffuseable dyes on development

electron transfer agents

Examples of other UVA materials which may be used in combination withthe instant compounds include

1. Benzophenones

2,4-dihydroxy-benzophenone

2-hydroxy-4-ethoxy-benzophenone

2,2'-dihydroxy-4-methoxy-benzophenones

2-hydroxy-4-n-octoxy-benzophenone

2-hydroxy-4-isooctoxy-benzophenone

2-hydroxy-4-dodecyloxy-benzophenone

2. Benzotriazoles:

2-(2-hydroxy-5-methylphenyl)-benzotriazole,

2-(2-hydroxy-3,5-di-t-butylphenyl)-benzotriazole,

2-(2-hydroxy-3-t-butyl-5-ethylphenyl)-5-chlorobenzotriazole,

2-(2-hydroxy-3,5-di-t-butylphenyl)-5-chlorobenzotriazole,

2-(2-hydroxy-3,5-di-tert-amylphenyl)-benzotriazole,

2-(2-hydroxy-3-s-butyl-5-t-butylphenyl)-benzotriazole,

2-(2-hydroxy-5-t-butylphenyl)-benzotriazole,

2-(2-hydroxy-5-t-octylphenyl)-benzotriazole,

a mixture of 50% of2-[(2-hydroxy-3-t-butyl-5-((2"-n-octoxy-carbonyl)-ethyl)phenyl]-5-chlorobenzotriazoleand 50% of2-[(2-hydroxy-3-t-butyl-5-((2"-ethylhexyloxy)carbonyl)ethyl)phenyl]-5-chlorobenzotriazole,

2-[2-hydroxy-3,5-di-(alpha,alpha-dimethylbenzyl)phenyl]-benzotriazole

3. Benzylidene malonates

methyl-2-carboxymethyl-3-(4'-methoxyphenyl)-acrylate

4. Salicylates

p-octylphenyl salicylate

phenyl salicylate

t-butylphenyl salicylate

5. Monobenzoates

Resorcinol monobenzoate

3,5-di-t-butyl-4-hydroxybenzoic acid

hexadecyl ester

6. Oxamides

5-t-butyl-2-ethoxy-2'2'-ethyloxanilide,

2-ethoxy-2'-ethyloxanilide

7. 5-dialkylamino-2,4-pentadienoic acid esters

diethylamino-2-phenylsulphonyl-2,4-pentadienoic acid hexadecylester

8. 5-dialkylamino-2-cyano-2,4-pentadiene nitriles

5-dihexylamino-2-cyano-2,4-pentadiene nitrile

9. 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate,

3,5-ditertieary-butyl-p-hydroxy-benzoic acid,

di(1,2,2,6,6-pentamethyl-4-piperidinyl)-butyl(3',5'-di-t-butyl-4-hydroxybenzyl)malonate,

bis(1,2,6,6-tetramethyl-4-piperidinyl) sebacate,

bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate,

butane tetracarboxylic acid

tetra(2,2,6,6-tetramethyl-4-piperidinyl)ester

The instant compounds may also be used in cyan layers together witheither phenol, naphthol or 2,5-diacylaminophenol couplers or mixtures ofthese couplers to prevent image fading and discoloration.

The use of known benzotriazoles in such systems is described in JapaneseKokai Nos. Sho 58-221,844 and 59-46,646.

The compounds of this invention are effective light tabilizers in a widerange of organic polymers. Polymers which can be stabilized include:

1. Polymers which are derived from mono- or diolefins, e.g.,polyethylene which can optionally be crosslinked, polypropylene,polyisobutylene, polymethylbutene-1, polymethylpentene-1, polyisoprene,polybutadiene.

2. Mixtures of the homopolymers cited under (1), for example mixtures ofpolypropylene and polyethylene, polypropylene and polybutene-1,polypropylene and polyisobutylene.

3. Copolymers of the monomers based on the homopolymers cited under (1),for example ethylene/propylene copolymers, propylene/butene-1copolymers, propylene/isobutylene copolymers, ethylene/butene-1copolymers as well as terpolymers of ethylene and propylene with adiene, for example hexadiene, dicyclopentadiene or ethylidenenorbornene, and copolymers of α-olefins, e.g., ethylene with acrylic ormethacrylic acid, and blends of such copolymers with homopolymersdescribed in paragraphs 1 and 2 above.

4. Polystyrene.

5. Copolymers of styrene and of α-methylstyrene, for examplestyrene/butadiene copolymers, styrene/acrylonitrile copolymers,styrene/acrylonitrile/methacrylate copolymers, styrene/acrylonitrilecopolymers modified with acrylic ester polymers to provide impactstrength as well as block copolymers, e.g., styrene/butadiene/styrene,styrene/isoprene/styrene and styrene/ethylene-propylene/styrene blockcopolymers.

6. Graft copolymers of styrene, for example the graft polymer of styreneto polybutadiene, the graft polymer of tyrene with acrylonitrile topolybutadiene as well as mixtures thereof with the copolymers citedunder (5), commonly referred to as acrylonitrile/butadiene/styrene orABS plastics.

7. Halogen-containing vinyl polymers, for example polyvinyl chloride,polyvinylidene chloride, polyvinyl fluoride, polychloroprene,chlorinated rubbers, vinyl chloride/vinylidene chloride copolymers,vinyl chloride/vinyl acetate copolymers, vinylidene chloride/vinylacetate copolymers.

8. Linear and crosslinked polymers which are derived fromα,β-unsaturated acids and derivatives thereof, such as polyacrylates andpolymethacrylates, polyacrylic amides and polyacrylonitrile.

9. Polymers which are derived from unsaturated alcohols and amines andfrom the acyl derivatives thereof or acetals, for example polyvinylalcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate,polyvinyl maleate, polyvinyl butyral, polyallyl phthalate, polyallylmelamine and copolymers thereof with other vinyl compounds, for exampleethylene/vinyl acetate copolymers.

10. Homopolymers and copolymers which are derived from epoxides, forexample polyethylene oxide or the polymers which are derived frombis-glycidyl ethers.

11. Polyacetals, for example polyoxymethylene, as well aspolyoxymethylenes which contain ethylene oxide as comonomer.

12. Polyalkylene oxides, for example polyoxyethylene, polypropyleneoxide or polybutylene oxide.

13. Polyphenylene oxides, and blends of polyphenylene oxides with impactresistant polystyrene.

14. Polyurethanes and polyureas, such as in urethane coatings.

15. Polycarbonates.

16. Polysulfones.

17. Polyamides and copolyamides which are derived from diamines anddicarboxylic acids and/or from aminocarboxylic acids or thecorresponding lactams, for example polyamide 6, polyamide 6/6, polyamide6/10, polyamide 11, polyamide 12, poly-m-phenylene-isophthalamide.

18. Polyesters which are derived from dicarboxylic acids and dialcoholsand/or from hydroxycarboxylic acids or the corresponding lactones, forexample polyethylene glycol terephthalate,poly-1,4-dimethylol-cyclohexane terephthalate.

19. Cross-linked polymers which are derived from aldehydes on the onehand and from phenols, ureas and melamine on the other, for examplephenol/formaldehyde, urea/formaldehyde and melamine/formaldehyde resin.

20. Alkyd resins, for example glycerol/phthalic acid resins and mixturesthereof with melamine/formaldehyde resins.

21. Unsaturated polyesters resins which are derived from copolyesters ofsaturated and unsaturated dicarboxylic acids with polyhydric alcohols aswell as from vinyl compounds as cross-linking agents and also thehalogen-containing, flame-resistant modifications thereof.

22. Natural polymers, for example cellulose, rubber, as well as thechemically modified homologous derivatives thereof, for examplecellulose acetates, cellulose propionates and cellulose butyrates andthe cellulose ethers, for example methyl cellulose.

The stabilizing of polyolefins, styrene polymers, polyacrylates,polyamides, polyurethanes, halogen containing vinyl polymers, alkydresins, thermoset acrylic resins, and epoxy resins is of particularimportance, and the instant benzotriazole mixtures are outstandinglysuitable for this purpose. Examples of such polymers are high densityand low density polyethylene, polypropylene, ethylene/propylenecopolymers, polystyrene, styrene block copolymers, halogen containingvinyl polymers, linear (=thermoplastic) and crosslinked (=thermoset)polyacrylates and polyurethanes, alkyd resins and epoxy resins in theform of coatings, lacquers, filaments, films, sheets, adhesives,elastomers, foams or shaped articles.

The instant stabilizers are added to the substrates in a concentrationof 0.05 to 10% by weight, calculated relative to the material to bestabilized. Preferably, 0.1 to 5% by weight of the stabilizer calculatedrelative to the material to be stabilized, is incorporated into thelatter.

Incorporation can be effected after polymerization, for example bymixing the compounds and, if desired, further additives into the melt bythe methods customary in the art, before or during shaping, or byapplying the dissolved or dispersed compounds to the polymer, withsubsequent evaporation of the solvent if necessary.

The stabilizers can also be added to the substrates to be stabilized inthe form of a master batch which contains these compounds, for examplein a concentration of 2.5 to 25% by weight.

Although the compounds of the invention may be used to provide a lightstabilizing function, the compounds of this invention are often combinedwith other stabilizers, even other light stabilizers, in the preparationof stabilized compositions. The stabilizers may be used with phenolicantioxidants, pigments, colorants or dyes, light stabilizers such ashindered amines, metal deactivators, etc.

In general, the stabilizers of this invention are employed from about0.05 to about 10% by weight of the stabilized composition, although thiswill vary with the particular substrate and application. An advantageousrange is from about 0.1 to about 5%.

The stabilizers of Formula I or II may readily be incorporated into theorganic substrates by conventional techniques, at any convenient stageprior to the manufacture of shaped articles therefrom. For example, thestabilizer may be mixed with the dry polymer, or a suspension, solutionor emulsion of the stabilizer may be mixed with a solution, suspension,or emulsion of the polymer. The stabilized polymer compositions of theinvention may optionally also contain from about 0.05 to about 10%,preferably from about 0.1 to about 5%, by weight of various conventionaladditives, such as the following, particularly phenolic antioxidants orlight-stabilizers, or mixtures thereof:

1. Antioxidants

1.1 Simple 2,6-dialkylphenols, such as, for example,2,6-di-tert.-butyl-4-methylphenol, 2-tert.-butyl-4,6-dimethylphenol,2,6-di-tert.-butyl-4-methoxymethylphenol and2,6-dioctadecyl-4-methylphenol.

1.2 Derivatives of alkylated hydroquinones, such as for example,2,5-di-tert.-butyl-hydroquinone, 2,5-di-tert.-amylhydroquinone,2,6-di-tert.-butyl-hydroquinone, 2 5-di-tert.-butyl-4-hydroxy-anisole,3,5-di-tert.-butyl-4-hydroxy-anisole, 3,5-di-tert.-butyl-4-hydroxyphenylstearate and bis-(3,5-di-tert.-butyl-4-hydroxyphenyl) adipate.

1.3 Hydroxylated thiodiphenyl ethers, such as for example,2,2'-thio-bis-(6-tert.-butyl-4-methylphenol),2,2'-thio-bis-(4-octylphenol),4,4'-thio-bis-(tert.-butyl-3-methylphenol),4,4'-thio-bis-(3,6-di-sec.-amylphenol),4,4'-thio-bis-(6-tert.-butyl-2-methylphenol) and4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl) disulfide.

1.4 Alkylidene-bisphenols, such as, for example,2,2'-methylene-bis-(6-tert.-butyl-4-methylphenol),2,2'-methylene-bis-(6-tert.-butyl-4-ethylphenol),4,4'-methylene-bis-(6-tert.-butyl-2-methylphenol),4,4'-methylene-bis-(2,6-di-tert.-butyl-phenol),2,6-di-(3-tert.-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,2,2'-methylene-bis-[4-methyl-6-(-methylcycloexyl)-phenol],1,1-bis(3,5-dimethyl-2-hydroxyphenyl)-butane,1,1-bis-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-butane,2,2-bis-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propane,1,1,3-tris-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-butane,2,2-bis-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecyl-mercapto-butane,1,1,5,5-tetra-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-pentane andethylene glycol bis-[3,3-bis-(3-tert.-butyl-4-hydroxyphenyl)-butyrate].

b 1.5 O-, N- and S-benzyl compounds, such as for example, 3,5,3',5'-tetra-tert.-butyl-4,4'-dihydroxydibenzyl ether, octadecyl4-hydroxy-3,5-dimethylbenzyl-mercaptoacetate,tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-amine andbis-(4-tert.-butyl-3-hydroxy-2,6-dimethylbenzyl) dithioterephthalate.

1.6 Hydroxybenzylated malonates, such as for example, dioctadecyl2,2-bis-(3,5-di-tert.-butyl-2-hydroxybenzyl)-malonate, dioctadecyl2-(3-tert.-butyl-4-hydroxy-5-methylbenzyl)malonate,di-dodecylmercapto-ethyl2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate anddi-[4-(1,1,3,3-tetramethylbutyl)phenyl]2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate.

1.7 Hydroxybenzyl-aromatic compounds, such as, for example,1,3,5-tri-(3,5-di-tert.-butyl-4-hydroxybenzyl)-2,4,6-trimethyl-benzene,1,4-di-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzeneand 2,4,6-tri-(3,5-di-tert.-butyl-4-hydroxy-benzyl)-phenol.

1.8 s-Triazine compounds, such as, for example2,4-bis-octylmercapto-6-(3,5-di-tert.-butyl-4-hydroxy-anilino)-s-triazine,2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyanilino)-s-triazine,2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-s-triazine,2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-s-triazine,2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxphenylethyl)-s-triazine and1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl) isocyanurate.

1.9 Amides of β-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionic acids,such as, for example1,3,5-tris-(3,5,-di-tert.-butyl-4-hydroxyphenyl-propionyl)-hexahydro-s-triazineandN,N'-di-(3,5-di-tert.-butyl-4-hydroxyphenyl-propionyl)-hexamethylenediamine,N,N'-bis-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl-hydrazine.

1.10 Esters of β-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionic acidwith monohydric or polyhydric alcohols, such as for example, withmethanol, ethanol, octadecanol, 1,6-hexanediol;. 1,9-nonanediol,ethylene glycol, 1,2-propane-diol, diethylene glycol, thiodiethyleneglycol, neopentylglycol, pentaerythritol, 3-thiaundecanol,3-thia-pentadecanol, trimethylhexanediol, trimethylolethane,trimethylolpropane, tris-hydroxyethyl isocyanurate and4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-[2.2.2]octane.

1.11 Esters of β-(5-tert.-butyl-4-hydroxy-3-methylphenyl)propionic acidwith monohydric or polyhydric alcohols, such as for example, withmethanol, ethanol, octadecanol, 1,6-hexanediol, 1-9-nonanediol, ethyleneglycol, 1,2-propanediol, di-ethylene glycol, thiodiethylene glycol,neopentylglycol, pentaerythritol, 3-thia-undecanol, 3-thia-pentadecanol,trimethylhexanediol, trimethylolethane, trimethylolpropane,tris-hydroxyethyl isocyanurate and4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2.]octane.

1.12 Esters of 3,5-di-tert.-butyl-4-hydroxyphenylacetic acid withmonohydric or polyhydric alcohols, such as for example, with methanol,ethanol, octadecanol, 1,6-hexandiol, 1,9-nonanediol, ethylene glycol,1,2-propenediol, diethylene glycol, thiodiethylene glycol,neopentylglycol, pentaerythritol, 3-thia-undecanol, 3-thia-pentadecanol,trimethylhexanediol, trimethylolethane, trimethylolpropane,tris-hydroxyethyl isocyanurate and4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2 2.2]-octane, especiallythe tetrakis ester of pentaerythritol.

1.13 Benzylphosphonates, such as, for example, dimethyl3,5-di-tert.-butyl-4-hydroxybenzylphosphonate, diethyl3,5-di-tert.-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert.-butyl-4-hydroxybenzylphosphonate and dioctadecyl5-tert.-butyl-4-hydroxy-3-methylbenzylphosphonate.

2. Light-stabilizers

2.1 Esters of optionally substituted benzoic acids, e.g.,3,5-di-tert.-butyl-4-hydroxybenzoic acid, 2,4-di-tert.-butylphenyl esteror -octadecyl ester or 2-methyl-4,6-di-tert.-butylphenyl ester.

2.2 Sterically hindered amines e.g.,4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethyl-piperidine,bis-(2,2,6,6-tetramethylpiperidyl) sebacate,bis-(1,2,2,6,6-pentamethylpiperidyl) sebacate,bis-(1,2,2,6,6-pentamethylpiperidyl)2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate or3-n-octyl-7,7,9,9-tetra-methyl-1,3,8-triazaspiro[4.5]decane-2,4-dione.

2.3 Oxalic acid diamides, e.g., 4,4'-di-octyloxy-oxanilide,2,2'-di-octyloxy-5,5'-di-tert.butyl-oxanilide,2,2'-di-dodecycloxy-5,5'-di-tert.-butyl-oxanilide,2-ethoxy-2'-ethyloxanilide, N,N'-bis-(3-dimethyl-aminopropyl)-oxalamide,2-ethoxy-5-tert.-butyl-2'-ethyl-oxalamide, and the mixture thereof with2-ethoxy-2'-ethyl-5,4'-di-tert.-butyl-oxanilide, or mixture of ortho-and para-methoxy- as well as of o- and p-ethoxy-di-substitutedoxanilides.

3. Metal deactivators, e.g., oxanilide, isophthalic acid dihydrazide,sebacic acid-bis-phenylhydrazide, bis-benzylidene-oxalic aciddihydrazide, N,N'-diacetal-adipic acid dihydrazide,N,N'-bis-salicyloyl-oxalic acid dihydrazide,N,N'-bis-salicyloylhydrazine,N,N'-bis-(3,5-di-tert.-butyl-4-hydroxyphenylpropionyl)-hydrazine,N-salicyloyl-N'-salicylalhydrazine, 3-salicyloyl-amino-1,2,4-triazole orN,N,'-bis-salicyloyl-thiopropionic acid dihydrazide.

4. Basic co-stabilizers, e.g., alkali metal salts and alkaline-earthmetal salts of higher fatty acids, for example Ca-stearate, Zn-stearate,Mg-behenate, Na-ricinoleate or K-palmitate.

5. Nucleation agents, e.g., 4-tert.-butylbenzoic acid, adipic acid ordiphenylacetic acid.

6. Phosphites and phosphonites, such as, for example, triphenylphosphite, diphenylalkyl phosphites, phenyldialkyl phosphites,tri-(nonyl-phenyl) phosphite, trilauryl phosphite, trioctadecylphosphite and3,9-isodecyloxy-2,4,8,10-tetraoxa-3,9-diphospha-[5.5]-undecane andtetra(2,4-di-tert-butylphenyl) diphenylene-4,4'-bis(phosphonite).

Other additives that can be incorporated in the stabilized compositionsare thiosynergists such as dilauryl thiodiproprionate, lubricants suchas stearyl alcohol, fillers, asbestos, kaolin, talc, glass fibers,pigments, optical brighteners, flameproofing agents and antistaticagents.

The following examples are presented for the purpose of illustrationonly and are not to be construed to limit the nature or scope of theinstant invention in any manner whatsoever.

EXAMPLE 1 2-(2-Hydroxy-3-octyl-5-methylphenyl)-2H-benzotriazole

In a flask fitted with an nitrogen blanket, stirrer, reflux condenserand addition funnel, 225 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 65 ml of methanesulfonicacid and 156 ml of 1-octene are heated at 120° C. for a six-hour period.Throughout said period another 467 ml of 1-octene is added to thereaction mixture. The mixture is then cooled and extracted with two 200ml portions of methanolic potassium hydroxide solution (40 gramspotassium hydroxide in 100 ml of methanol). The extracts are washed with1×400 ml and then with 4×200 ml of heptane. Water (200 ml) is added tothe heptane extracts and the upper heptane layer is separated, washedwith 5×200 ml of aqueous methanol (methanol 2:water 1). The washedheptane layer is dried over anhydrous magnesium sulfate and treated with1×10 grams and then 1×5 grams of an acidic absorbent clay (FILTROL 13).After removal of the clay absorbent, the heptane solution is vacuumstripped at 110° C./2 mm to give 23 grams of the above-named product asa yellow liquid.

Analysis: Calcd for C₂₁ H₂₇ N₃ O: C, 74.7; H, 8.0; N, 12.4. Found: C,74.3; H, 7.9; N, 11.8.

Formula weight is 337.4.

Weight found by titration is 337.

In like manner,5-chloro-2-(2-hydroxy-3-octyl-5-methylphenyl)-2H-benzotriazole isprepared by substituting for the benzotriazole used above an equivalentamount of 5-chloro-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole.

EXAMPLE 2 2-(2-Hydroxy-3-decyl-5-methylphenyl)-2H-benzotriazole

Using the general procedure of Example 1, 225 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 65 ml of methanesulfonicacid and 188 ml of 1-decene are heated at 160° C., for a 5-hour periodduring which time another 564 ml of 1-decene is gradually added to thereaction mixture. The mixture is then cooled and the product isolated bythe method described in Example 1 to give 183 grams of the above-namedproduct as a yellow liquid.

Analysis: Calcd for C₂₃ H₃₁ N₃ O: C, 75.6; H, 8.55; N, 11.5. Found: C,75.6; H, 8.7; N, 11.5.

Formula weight is 365.

Weight found by titration is 394.

In like manner,5-chloro-2-(2-hydroxy-3-decyl-5-methylphenyl)-2H-benzotriazole isprepared by substituting for the benzotriazole used above an equivalentamount of 5-chloro-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole.

EXAMPLE 3 2-(2-Hydroxy-3-dodecyl-5-methylphenyl)-2H-benzotriazole

Using the general procedure of Example 1, 225 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 65 ml of methanesulfonicacid and 222 ml of 1-dodecene are heated at 160° C. for four hours. Overthis 4-hour period another 666 ml of 1-dodecene is added to the reactionmixture. The mixture is then cooled and the product isolated by themethod described in Example 1 to give 187 grams of the above-namedproduct as a yellow oil.

Analysis: Calcd for C₂₅ H₃₅ N₃ O: C, 76.3; H, 9.0; N, 10.7. Found: C,76.4; H, 9.0; N, 10.5.

Formula weight is 393.5.

Weight found by titration is 395.

In like manner,5-chloro-2-(2-hydroxy-3-dodecyl-5-methylphenyl-2H-benzotriazole isprepared by substituting for the benzotriazole used above an equivalentamount of 5-chloro-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole.

EXAMPLE 4 2-(2-Hydroxy-3-hexadecyl-5-methylphenyl)-2H-benzotriazole

Using the general procedure of Example 1, 225 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 65 ml of methanesulfonicacid and 222 ml of 1-hexadecene are heated at 160° C. for six hours.Over this 6-hour period another 856 ml of 1-hexadecene is added to thereaction mixture. The mixture is then cooled and the product isolated bythe general method described in Example 1. The heptane solution of theproduct is stripped at 280° C./2 mm to remove the heptane and anyresidual 1-hexadecene. The residue is then dissolved in petroleum etherfor treatment with the acidic absorbent clay. The petroleum ether isthen stripped to give 124.5 grams of the above-named product as anorange liquid.

Analysis: Calcd for C₂₉ H₄₃ N₃ O: C, 77.5; H,9.6; N,9.3. Found: C, 77.2;H,9.3; N,9.0.

Formula weight is 449.

Weight found by titration 483.

In like manner,5-chloro-2-(2-hydroxy-3-hexadecyl-5-methylphenyl)-2H-benzotriazole isprepared by substituting for the benzotriazole used above an equivalentamount of 5-chloro-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole.

EXAMPLE 5 2-(2-Hydroxy-3-eicosyl-5-methylphenyl)-2H-benzotriazole and2-(2-Hydroxy-3-docosyl-5-methylphenyl)-2H-benzotriazole

Using the general procedure of Example 1, 225 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 65 ml of methanesulfonicacid and 368 ml of GULFTENE 20-24 (which is essentially a 50/50 mixtureof 1-eicosene and 1-docosene) are heated at 160° C., for five hours.Over this 5-hour period, another 854 ml of GULFTENE 20-24 is added tothe reaction mixture. The reaction mixture is cooled to about 50° C. and400 ml of petroleum ether is added to facilitate isolation of theproduct by the general method described in Example 1. The twoabove-named products are obtained as a 50/50 mixture as a yellow liquid.

Analysis: Calculated for the mixture C₃₄ H₅₃ N₃ O; C, 78.6; H,10.3;N,8.1. Found: C, 78.8; H,10.5; N,8.0.

In like manner, a mixture of the5-chloro-2-(2-hydroxy-3-eicosyl-5-methylphenyl)-2H-benzotriazole and5-chloro-2-(2-hydroxy-3-docosyl-5-methylphenyl)-2H-benzotriazole isprepared by substituting for the benzotriazole used above an equivalentamount of 5-chloro-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole.

EXAMPLE 6 2-(2-Hydroxy-3-dodecyl-5-methylphenyl)-2H-benzotriazole

Using the general procedure of Example 1, 225 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 65 ml of methanesulfonicacid and 225 ml of propylene tetramer (4,6,8-trimethyl-2-nonene and itsisomers) are heated at 160° C. for six hours. Over said 6-hour period,another 675 ml of propylene tetramer is added to the reaction mixture.The mixture is cooled and the product isolated by the general methoddescribed in Example 1 to give 30.9 grams of the above-named product asa yellow oil.

Analysis: Calcd for C₂₅ H₃₅ N₃ O: C, 76.3; H,9.0; N,10.7. Found: C,76.1;H,8.9; N,10.7.

In like manner,5-chloro-2-(2-hydroxy-3-dodecyl-5-methylphenyl)-2H-benzotriazole isprepared by substituting for the benzotriazole used above an equivalentamount of 5-chloro-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole.

EXAMPLE 7 2-(2-Hydroxy-3-tetracosyl-5-methylphenyl)-2H-benzotriazole

Using the general procedure of Example 1, 112 grams of2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 33 ml of methanesulfonicacid and 444 ml (2 moles) of a mixture of tetracosenes (prepared by thedimerization of n-dodecene) are heated at 160° C.; for 96 hours. Thereaction mixture is cooled and the product isolated by the generalprocedure described in Example 1. The excess hydrocarbons are removed bydistillation at 190° C./0.04 mm. The above-named product is obtained ina yield of 103.6 grams as a yellow liquid. The liquid still containedinert hydrocarbon diluents which are removed by flash chromatographyusing silica gel and heptane/toluene 75/25 to give a pure product in ayield of 15 grams as a yellow liquid.

Analysis Calcd for C₃₇ H₅₉ N₃ O: C,79.1; H,10.6; N,7.5. Found: C, 79.3;H,10.4; N,8.1.

EXAMPLE 8 Light Stabilization of Automotive Topcoat

A thermoset acrylic resin coating composition, typical for automotivetopcoats, is formulated with 2% by weight of the light stabilizerprepared in Example 3. The coating composition is applied to a metalpanel and baked at 130° C. to cure the resin. The coated panel is thenexposed to accelerated (quick) weathering test (QUV) involvingalternating 8-hour period of UV irradiation at 70° C. with a 4-hourperiod of condensation (rain) at 50° C. for each cycle for a total of980 hours.

The 20° gloss (ASTM D523 and D2457) and the Distinctness of Image (ASTME 430) values for the coating before and after weathering in the QUVtest are measured and the % retention of 20° gloss and of distinctnessof image (D/I) are calculated. The control is the same thermoset acrylicresin coating containing no stabilizer.

The results are shown in the table below.

    ______________________________________                                        Coating Properties after                                                      980 Hours Exposure in QUV                                                     Thermoset                                                                     Acrylic   Surface    % 20° Gloss                                                                       % Retention                                   Resin*    Cracked    Retention  of D/I                                        ______________________________________                                        Control   yes        42         38                                            (Unstabilized)                                                                Containing                                                                              no         72         97                                            2% by wt.                                                                     stabilizer                                                                    of Example 3                                                                  ______________________________________                                          *Thermoset acrylic enamel is based on a binder of 70% of acrylic monomer     such as hydroxyethyl acrylate, styrene, acrylonitrile, butyl acrylate and     acrylic acid with 30% of a melamine resin.                               

The stabilized coating exhibits far superior gloss and D/I retentionthan the unstabilized control. The stabilized sample shows no sign ofsurface cracking or crazing again showing the efficacy of the instantcompounds as light stabilizers.

EXAMPLE 9

An oil-modified urethane varnish containing 2% by weight of thestabilizer prepared in Example 3 is coated on an aluminum panel andexposed outdoors at a 90° angle facing south in Southern New York for aperiod of 10.5 months.

The yellowness index (YI), measured by ASTM D 1925, for the sample ismeasured before exposure and after exposure. The change in YI is ameasure of how much the urethane coating discolored over the testperiod. The lower the change in YI the less discolored is the sample.

    ______________________________________                                        Oil-Modified Urethane Varnish After                                           10.5 Months Outdoors Exposure                                                                 Change   % Gloss (20°)                                 Sample          in YI    retention                                            ______________________________________                                        Control          14      95                                                   (unstabilized)                                                                Sample containing                                                                             -3.4     96                                                   2% by weight                                                                  of mixture of                                                                 Example 3                                                                     ______________________________________                                    

Gloss retention values are the same, but the urethane varnish containingthe instant benzotriazoles of Example 3 does not yellow whereas thecontrol turned perceptily discolored (yellowed).

EXAMPLE 10 Haze Development in Photographic Compositions

The direct assessment of the compatibility of benzotriazole lightstabilizers in photographic compositions is difficult. The compositionscontaining such stabilizers in photographic oils often take extendedperiods of time for separation or haze to be observed.

An important property of photographic compositions directly related tosuch compatibility parameters related to such compatibility parametersis haze. For the preparation of clear and precise preparation of clearand precise photographic images, haze must obviously be minimized orbetter yet essentially eliminated.

Using the procedure described in U.S. Pat. No. 4,383,863, Example 5, aUV-protecting layer is prepared in gelatin containing an anionic wettingagent, a hardener and the instant stabilizer of Example 3 using nosolvent.

A very fine dispersion of the instant stabilizer in this gelatincomposition is produced by ultrasonic mixing to give a UV-protectinglayer which is clear and transparent and exhibits no haze.

What is claimed is:
 1. A process for preparing a normally liquid ornon-crystalline mixture of benzotriazoles, suitable for stabilizingorganic materials against light induced deterioration, which consistsessentially of compounds of the formula ##STR11## wherein T₁ is hydrogenor chloro, andT₂ is a random statistical mixture of at least threeisomeric branched secondary alkyl groups each having 8 to 30 carbonatoms and having the formula ##STR12## where E₁ is a straight chainalkyl of 1 to 14 carbon atoms and E₂ is a straight chain alkyl of 4 to15 carbon atoms where the total number of carbon atoms in E₁ plus E₂ is7 to 29, which process comprises alkylating a benzotriazole of theformula ##STR13## where T₁ is hydrogen or chloro, with a straight chainalkene of 8 to 30 carbon atoms in the presence of an acidic catalyst ata temperature of 100 to 200° C.,wherein the equivalent ratio of alkeneto 2H-benzotriazole is 1:1 to 6:1, and the equivalents of acidiccatalyst selected from the groups consisting of aliphatic, aromatic andsubstituted aromatic sulfonic acids, sulfuric acid, phosphoric acid,acidic clays and acidic molecular sieves per equivalent of benzotriazoleis 0.2 to
 3. 2. A process according to claim 1 wherein T₁ is hydrogen.3. A process according to claim 1 wherein T₂ is alkyl of 8 to 16 carbonatoms.
 4. A process according to claim 3 wherein T₂ is alkyl of 10 to 12carbon atoms.
 5. A process according to claim 1 wherein the temperatureis 140° to 170° C.
 6. A process according to claim 5 wherein thetemperature is 160°-165° C.
 7. A process according to claim 1 whereinthe equivalent ratio of alkene to 2H-benzotriazole is 3.5:1 to 4.5:1. 8.A process according to claim 1 wherein the acidic catalyst is analiphatic sulfonic acid.
 9. A process according to claim 8 wherein theacidic catalyst is methanesulfonic acid.
 10. A process according toclaim 1 wherein the per equivalent of acidic catalyst to equivalents ofbenzotriazole is 0.3 to
 2. 11. A process according to claim 10 whereinthe per equivalent of acidic catalyst to equivalents of benzotriazole is0.5 to
 1. 12. A process for preparing a normally liquid ornon-crystalline mixture of benzotriazoles, suitable for stabilizingorganic materials against light induced deterioration, which consistsessentially of compounds of the formula ##STR14## wherein R₁ is hydrogenor chloro, andR₂ is a random statistical mixture of at least threeisomeric branched alkyl groups each having 8 to 30 carbon atoms andhaving a multiplicity of alkyl branches along the main alkyl chain,which process comprises alkylating a benzotriazole of the formula##STR15## where R₁ is hydrogen or chloro, with a branched chain alkeneof 8 to 30 carbon atoms in the presence of an acidic catalyst at atemperature of 100° to 200° C.,wherein the equivalent ratio of alkene to2H-benzotriazole is 1:1 to 6:1, and the equivalents of acidic catalystselected from the groups consisting of aliphatic, aromatic andsubstituted aromatic sulfonic acids, sulfuric acid, phosphoric acid,acidic clays and acidic molecular sieves per equivalent of benzotriazoleis 0.2 to
 3. 13. A process according to claim 12 wherein R₁ is hydrogen.14. A process according to claim 12 wherein R₂ is alkyl of 8 to 16carbon atoms.
 15. A process according to claim 14 wherein R₂ is alkyl of9 to 12 carbon atoms.
 16. A process according to claim 12 wherein thetemperature is 140° to 170° C.
 17. A process according to claim 16wherein the temperature is 160°-165° C.
 18. A process according to claim12 wherein the equivalent ratio of alkene to 2H-benzotriazole is 3.5:1to 4.5:1.
 19. A process according to claim 12 wherein the acidiccatalyst is an aliphatic sulfonic acid.
 20. A process according to claim12 wherein the acidic catalyst is methanesulfonic acid.
 21. A processaccording to claim 12 wherein the equivalent of acidic catalyst toequivalents of benzotriazole is 0.3 to
 2. 22. A process according toclaim 21 wherein the equivalent of acidic catalyst to equivalents ofbenzotriazole is 0.5 to 1.